The instant invention relates to electrical switching devices and more particularly to a waterproof switching device which is adapted for use in small appliances for simultaneously interrupting the electrical continuity in two different lines of an electrical circuit.
Public awareness in the area of consumer safety has increased significantly over the past several years; and, as a result, it has been found to be necessary to modify or redesign many items, such as small appliances, in order to make them safer for consumers. In particular, it has been found to be necessary to redesign many small electrical appliances, such as hair dryers and the like, in order to prevent consumers from being accidentally electrocuted in the event that such items are inadvertently short circuited with water. For example, heretofore it was possible for a consumer to be accidentally electrocuted in a bathtub if an appliance such as a hair dryer was accidentally dropped into the water. Further, heretofore an accident of this type was possible even if the switch on the appliance which was dropped into the water was in off position, since in most cases it was possible for water to produce a short circuit between otherwise interrupted electrical terminals in the appliance.
As a result of the need to redesign small appliances so that they are safer to operate and, in particular, so that consumers operating them are less likely to be electrocuted, a need has developed for an effective switching device which can be reliably used on a small appliance but which is not normally short circuited when it is immersed in a pool of water. Still further, a need has developed for a waterproof switching device of this general type which is adapted for operating an appliance at two different speeds but which must be manually held in a depressed position in order to maintain the appliance in an energized state.
Devices representing the closest prior art to the instant invention of which the applicants are aware are disclosed in the U.S. Pat. Nos. 2,181,068; to Riche 2,182,856; Eaton 2,295,456; Kaminky 2,354,027; Meyer 2,370,479; Kaminky 2,468,673; Eaton 2,469,686; Rohr 2,495,349; Haydon 2,700,079; Readeker 2,701,475; Lauder et al. 2,743,331; Roeser 2,840,656; Karleen 3,056,866; and Brown 4,209,677. However, since these devices fail to suggest a device having first and second contact assemblies of the type embodied in the switch of the instant invention, and since they also fail to suggest a device which can effectively perform the functions of the switch of the instant invention, they are believed to be of only general interest.
The instant invention provides an effective improved switching device which can be utilized for small electrical appliances, such as hair dryers and the like, and which overcomes many of the disadvantages of the heretofore-available switching devices. Specifically, the switching device of the instant invention comprises a housing, a first contact assembly in the housing which is operable for effecting and interrupting electrical continuity between first and second terminals on the exterior of the housing, and a second contact assembly in the housing which is operable for effecting and interrupting electrical continuity betweeen third and fourth or third and fifth electrical terminals on the exterior of the housing. The housing preferably comprises a waterproof housing having a main casing and a cover which is received on the casing and is deformable for manually actuating the first and second contact assemblies. The first contact assembly preferably comprises a fixed contact which is electrically connected to the first electrical terminal on the exterior of the housing and a resiliently movable stressed contact member which is electrically connected to the second terminal on the exterior of the housing. The stressed contact member has a free end, and it is constructed so that it is resiliently movable with a snap action between a first position wherein the free end thereof is spaced from the fixed contact and a second position wherein the free end thereof is in engagement with the fixed contact. The main portion of the stressed contact member is preferably integrally struck from a resilient sheet metal, and it preferably comprises a center leaf and two side leaves. The center and side leaves preferably have first ends which are integrally connected adjacent the free end of the stressed contact member and second ends which are secured in the switch so that the two side leaves are in compression and the center leaf is in tension in order to make the stressed contact member operable with a snap action. The second contact assembly preferably comprises a resiliently movable actuator contact member which is electrically connected to the third terminal on the exterior of the housing, a resiliently movable first blade member which is electrically connected to the fourth terminal on the exterior of the housing, and a resiliently movable second blade member which is electrically connected to the fifth terminal on the exterior of the housing. The actuator contact member is mounted in the housing so that it is electrically insulated from the stressed contact member but so that it is depressible to move the stressed contact member from the first position thereof to the second position thereof. The first and second resilient blade members are mounted in spaced relation in the housing so that they are each independently depressible to positions of engagement with the actuator contact member wherein the actuator contact member is thereby depressed and the stressed contact member is moved to the second position thereof. The switch preferably further comprises an intermediate actuator member which is interposed between the actuator contact member and the stressed contact member and electrically insulated from the actuator contact member. The intermediate actuator member is preferably mounted in the housing so that it is operative for securing the stressed contact member in the housing and so that it is depressible to depress the stressed contact member in order to move it to the second position thereof. The cover portion of the housing of the switch construction preferably comprises a first portion which is depressible to independently depress the first blade member of the second contact assembly and a second portion which is spaced from the first portion and depressible to independently depress the second blade member of the second contact assembly. In the preferred application of the switch construction of the instant invention, it is utilized in combination with a diode which is electrically connected between the fourth and fifth terminals on the exterior of the housing. It is also preferably utilized in combination with a waterproof power cord comprising first and second waterproof wire elements, the first wire element being electrically connected in waterproof relation to one of the first or second terminals, and the second wire element being electrically connected in waterproof relation to either the third terminal or to both of the fourth and fifth terminals.
For use and operation of the switch construction of the instant invention, it is electrically connected in an electrical appliance between a power cord and the operative electrical circuitry of the appliance, and preferably a diode is connected between the fourth and fifth terminals on the exterior of the housing. Accordingly, by manually depressing the first portion of the cover portion of the housing, the first blade element is manually depressed to electrically connect it to the actuator contact member and to electrically connect the stressed contact member to the fixed contact. As a result, electrical continuity is provided between the third terminal and the fourth terminal, and electrical continuity is also provided between the first terminal and the second terminal so that the appliance to which the switch is connected is electrically energized. Alternatively, the appliance can also be energized by depressing the second portion of the cover portion of the housing to independently depress the second blade element to a position of engagement with the actuator contact member and to also thereby depress the stressed contact member to a position of engagement with a fixed contact. In this regard, when the switch construction is utilized in combination with a diode which is electrically connected between the fourth and fifth terminals, one actuated position of the switch causes full power to be passed to the appliance, whereas the other actuated position of the switch causes the appliance to be operated at half power. In either case, however, if manual pressure is released from the cover portion of the switch, electrical continuity is interrupted in both the first contact assembly and the second contact assembly so that both sides of the circuit which lead to the appliance are electrically interrupted. Further, since the switch construction is preferably connected to a power cord in waterproof relation, the switch cannot normally be short circuited even if the appliance to which the switch is constructed and the switch itself are both immersed in a pool of water, so that a person bathing in a pool of water cannot normally be electrocuted.
Accordingly, it is a primary object of the instant invention to provide a switch construction for small appliances which is operable with increased safety.
Another object of the instant invention is to provide a waterproof switch construction which can be utilized to effect and interrupt electrical continuity in two lines of an electrical circuit by manipulating a portion of a cover of a housing of the switch.
A still further object of the instant invention is to provide an effective switch construction which can be utilized for an appliance, such as a hair dryer or the like, but which is not normally short circuited in the event that the appliance is accidentally immersed in a pool of water.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.